Changed redirect URL functionality in ServletInterface (parameter
SPECIAL_ACTION_REDIRECTURL):  Parameter value is now base64 encoded
because facebook does not allow url parameters with special characters.
Thanks to facebook for not documenting this fact and stackoverflow for
helping to solve

Rate + Facebook Login/Post button added to [Lollapaloozer]RateComposite
Button changes appearance depending on whether user is logged in to
facebook
Button starts the facebook login process if the user is not logged in to
FB
If the user is logged in to FB, takes them to a rate dialog and back to
RTF when done

Rate + Twitter Login/Post button added to [Lollapaloozer]RateComposite
Button changes appearance when user is logged in to Twitter
Button starts twitter auth if user is not logged in
[Button will work for posting on twitter in a future update]

Auth Provider Account ownership conflict is handled entirely within
RateThisFest UI using a dialog to give the user some idea what is wrong.

Image resources added for all 3 auth provider account types - sign in,
share(large), share(small)